package com.leetcode.partition17;

import java.io.*;

/**
 * @author `RKC`
 * @date 2022/1/25 9:32
 */
public class LC1688比赛中的配对次数 {

    private static final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    private static final BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));

    public static void main(String[] args) throws IOException {
        int n = Integer.parseInt(reader.readLine());
        writer.write(numberOfMatches(n) + "\n");
        writer.flush();
    }

    public static int numberOfMatches(int n) {
        return n - 1;
    }
}
